Acrania or Acraniata is a group of chordates which have no skull or cranium, head, brain, vertebral column and jaws but have notochord. All are marine, small in size and treated as lower or primitive chordates. This group is divided
Acrania or Acraniata is a group of chordates which have no skull or cranium, head, brain, vertebral column and jaws but have notochord. All are marine, small in size and treated as lower or primitive chordates. This group is divided